Grinding system with coolant subsystem

ABSTRACT

A grinding system with a coolant subsystem including a grinding tool having a grinding surface adapted to grind a part, a nozzle adapted to supply a coolant material, and an arm coupled to the nozzle and to the grinding tool and adapted to allow placement of the nozzle in multiple positions. Each of the positions of the nozzle is preferably substantially tangent to the grinding surface of the grinding tool, which optimizes the transfer of excess heat from the grinding tool and the part.

TECHNICAL FIELD

[0001] This invention relates generally to the machining field, and more specifically to an improved grinding system with a coolant subsystem.

BACKGROUND OF THE INVENTION

[0002] The machining of an inner race for a constant-velocity joint of an automobile is a complex process. In a related application, U.S. Ser. No. ______ filed ______ and owned by the same assignee (Attorney Docket No. 10541-543N201-0316), the inventor has described the method of machining a part using a single clamp on a chuck and an OD-type grinding tool on the part. One of the difficulties of using an OD-type grinding tool on an inner race for a constant-velocity joint is adequately transferring the excess heat from the grinding system. In conventional systems, the access heat is typically transferred by a coolant material sprayed at a fixed point between the grinding surface of the grinding tool and the outer surface of the part. In the process described in the related application, however, the grinding tool moves through an actuate path and the use of a conventional fixed nozzle to supply the coolant material would result in a less-than-desired transfer of the excess heat. For this reason, there is a need in the grinding field for a new and improved coolant subsystem.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003]FIG. 1 is a top view of a finished product machined with the preferred embodiment of the invention;

[0004]FIG. 2 is a perspective view of the finished product of FIG. 1

[0005]FIG. 3 is a cross-sectional view of the grinding system of the preferred embodiment of the invention;

[0006]FIG. 4 is a side view of the grinding system of FIG. 3, shown with the nozzle in a first position; and

[0007]FIG. 5 is a partial side view of the grinding system of FIG. 3, shown with the nozzle in a second position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

[0008] The following description of the preferred embodiment of the invention is not intended to limit the invention to this preferred embodiment, but rather to enable any person skilled in the grinding art to use this invention.

[0009] As shown in the FIGURES, the preferred embodiment of the invention includes a grinding tool 10 having a grinding surface 12 adapted to grind a part 14, a nozzle 16 adapted to supply a coolant material 18, and an arm 20 coupled to the nozzle 16 and to the grinding tool 10 and adapted to allow placement of the nozzle 16 in multiple positions. Each of the positions of the nozzle 16 is preferably substantially tangent to the grinding surface 12 of the grinding tool 10, which optimizes the transfer of excess heat from the grinding tool 10 and the part 14. The preferred embodiment of the invention has been specifically designed to machine an inner race for a constant-velocity joint having six ground ball tracks. The preferred embodiment, however, may be used, with or without additional machining devices, to machine any suitable part for any suitable environment having at least one ground surface.

[0010] As shown in FIGS. 1 and 2, the ball track 22 of the part preferably has a complex curvature including a concave curve along a plane defined by the X and Y axis and a convex curve along the Z axis. Although the concave curve is preferably machined by a simple rotation of the profile of the grinding tool 10, the convex curve is accomplished by an actuate movement of the part relative the grinding tool 10.

[0011] As shown in FIG. 3, the grinding tool 10 of the preferred embodiment is an OD-type grinding tool 10, which spins along an axis generally perpendicular to the rotational axis of the part. The grinding tool of a conventional system, in contrast, is an ID-type grinding tool, which generally spins along an axis parallel with the rotational axis of a part at a much higher speed than the OD-type grinding tool 10. In all other aspects, the OD-type grinding tool 10 is preferably a conventional device. The grinding tool 10 is preferably securely connected to a spindle 24. The spindle 24 functions to translate a rotational output from a first motor 26 to a rotational movement of the grinding tool 10. Both the spindle 24 and the first motor 26 are conventional devices, but may alternatively be any suitable device that functions to impart a rotation and torque on the grinding tool 10.

[0012] As shown in FIGS. 3 and 4, the nozzle 16 of the preferred embodiment functions to supply the coolant material 18. The coolant material 18, which functions to transfer the excess heat from the grinding tool 10 and the part 14, is preferably a conventional material, but may alternatively be any suitable material that functions to transfer excess heat. Although not necessary, the nozzle 16 is preferably shaped and sized to supply the coolant material 18 at the substantially same velocity as the grinding surface 12 of the grinding tool 10. This is preferably accomplished by using a predetermined velocity for the grinding surface 12 and adjusting the pressure of the coolant material 18 and the size and shape of the nozzle 16.

[0013] The performance of the coolant material 18 is optimized when sprayed from the nozzle 16 between the grinding tool 10 and the part 14 along a substantially tangent line to the grinding surface 12 of the grinding tool 10. Because the part is moved along an actuate path relative the grinding tool 10, the arm 20 of the preferred embodiment functions to allow placement of the nozzle 16 in multiple positions. As shown in FIGS. 4 and 5, the positions of the nozzle 16 are substantially tangent to the grinding surface 12 of the grinding tool 10, while armed to supply coolant material 18 between the grinding tool 10 and the part 14. In the preferred embodiment, a bearing collar 28, located around the spindle 24 of the grinding tool 10, functions to couple the spindle 24 and the arm 20 and to communicate the coolant material 18 from a reservoir (not shown) to the nozzle 16. This arrangement allows the arm 20 to pivot about the same rotational axis as the grinding tool 10. In alternative embodiments, other devices may be used to connect the arm 20 with the grinding system and to allow communication of the coolant material 18 to the nozzle 16. Just as the grinding tool 10 preferably moves along an actuate path to grind the ball track into the part 14, the arm 20 is preferably adapted to allow placement of the nozzle 16 along an arcuate path. The arm 20 is preferably moved through a connection with a second motor 30 and a belt 32, which functions to translate rotation of the second motor 30 into movement of the arm 20. Both the belt 32 and the second motor 30 are conventional devices, but may alternatively be any suitable devices to allow placement of the nozzle 16 in multiple positions.

[0014] The grinding system of the preferred embodiment also includes a controller 34, which functions to control the movement of the nozzle 16. The controller 34 is preferably a computer numeric control (“CNC”) device, but may alternatively be any suitable device that allows precise tracking of multiple devices within a machining system. The controller 34 is preferably coupled to a device (not shown) that moves the part relative the grinding tool 10 and, in this manner, the controller 34 is able to control the movement of the nozzle 16 based upon the location of the part relative the grinding tool 10. Other suitable devices or systems, of course, may alternatively be used to control the movement of the nozzle 16.

[0015] As any person skilled in the art of grinding systems will recognize from the previous description and from the figures and claims, modifications and changes can be made to the preferred embodiment of the invention without departing from the scope of this invention defined in the following claims. 

I claim:
 1. A coolant subsystem for a grinding tool having a spindle and a grinding surface, comprising: a nozzle adapted to supply a coolant material; an arm coupled to said nozzle and to said grinding tool and adapted to allow placement of said nozzle in multiple positions, each of said positions being substantially tangent to the grinding surface of the grinding tool; a motor connected to said arm and adapted to move said nozzle through each of said postions; and a controller coupled to said motor and adapted to control the movement of said nozzle to supply the coolant material based upon a location of a part relative the grinding tool.
 2. The coolant subsystem of claim 1, wherein said nozzle is adapted to supply the coolant material at the substantially same velocity as the grinding surface of the grinding tool.
 3. The coolant subsystem of claim 1, wherein said arm is coupled to the spindle of the grinding tool.
 4. The coolant subsystem of claim 3, wherein said nozzle pivots and the grinding tool rotates about the same axis.
 5. The coolant subsystem of claim 3, further comprising a bearing collar coupled around the spindle of the grinding tool and to said arm.
 6. The coolant subsystem of claim 1, wherein said arm is adapted to allow placement of said nozzle along an arcuate path.
 7. The coolant subsystem of claim 1, further comprising a belt coupled to said arm and to said motor and adapted to translate rotation of said motor into movement of said arm.
 8. The coolant subsystem of claim 1, wherein said controller is a computer numeric control (CNC) device.
 9. The coolant subsystem of claim 1, wherein said CNC device is further adapted to control the location of the part.
 10. A grinding system comprising: a grinding tool having a grinding surface adapted to grind a part; a spindle connected to said grinding tool; a first motor coupled to said spindle and adapted to rotate said spindle and said grinding tool; a nozzle adapted to supply a coolant material; an arm coupled to said nozzle and to said grinding tool and adapted to allow placement of said nozzle in multiple positions, each of said positions being substantially tangent to said grinding surface of said grinding tool; a second motor connected to said arm and adapted to move said nozzle through each of said positions; and a controller coupled to said second motor and adapted to control the movement of said nozzle to supply the coolant material based upon a location of the part relative said grinding tool.
 11. The grinding system of claim 10, wherein said nozzle is adapted to supply the coolant material at the substantially same velocity as the grinding surface of the grinding tool.
 12. The grinding system of claim 10, wherein said arm is coupled to the spindle of the grinding tool.
 13. The grinding system of claim 11, wherein said nozzle pivots and the grinding tool rotates about the same axis.
 14. The grinding system of claim 11, further comprising a bearing collar coupled around the spindle of the grinding tool and to said arm.
 15. The grinding system of claim 10, wherein said arm is adapted to allow placement of said nozzle along an arcuate path.
 16. The grinding system of claim 10, further comprising a belt coupled to said arm and to said motor and adapted to translate rotation of said motor into movement of said arm.
 17. The grinding system of claim 10, wherein said controller is a computer numeric control (CNC) device.
 18. The grinding system of claim 1, wherein said CNC device is further adapted to control the location of the part.
 19. A method of supplying coolant material for a grinding tool having a spindle and a grinding surface, comprising: providing a nozzle adapted to supply a coolant material; and moving the nozzle through multiple positions, each of the positions being substantially tangent to the grinding surface of the grinding tool, based upon a location of a part relative the grinding tool.
 20. The method of claim 19, further comprising supplying coolant material at the substantially same velocity as the grinding surface of the grinding tool.
 21. The method of claim 19, wherein said moving includes moving the nozzle along an arcuate path. 